1. Technical Field
The present invention relates to a multilayered phase difference plate formed by bonding multiple quartz crystal plates together, and a projector including this multilayered phase difference plate.
2. Related Art
A multilayered phase difference plate as disclosed in Patent Document 1 (JP-A-2004-170853) is known as an optical element for use in a liquid crystal projector or the like and for arranging the polarization of a light beam incident from a light source.
This multilayered phase difference plate includes two phase difference plates formed of quartz crystal substrates. The two phase difference plates are bonded together in a manner that the respective crystal optical axes (hereafter referred to as “optical axes”) thereof intersect each other. This multilayered phase difference plate serves as a half-wavelength phase difference plate and converts a polarization plane of an incident light beam into a 90°-rotated polarization plane. This incident light beam is a light beam in any one of a three-color wavelength range (approximately 400 nm to 700 nm), a blue wavelength range (approximately 400 nm to 500 nm), a green wavelength range (approximately 500 nm to 600 nm), and a red wavelength range (approximately 600 nm to 700 nm) according to the light source.
As disclosed in Patent Document 2 (JP-A-2006-330282), a liquid crystal projector or the like obtains light beams in the above-described multiple wavelength ranges from a light source using various optical elements, provides gradations to the obtained light beams using a liquid crystal shutter, and then synthesizes the resultant light beams again to project picture information. These optical elements forming an optical path include a number of phase difference plates. Incident light beams to these phase difference plates are in any one of the above-described wavelength ranges. Note that the ranges of the above-described wavelength ranges are one example and that ranges other than the above-described wavelength ranges are set according to the design of a liquid crystal projector.